# PSAP NG911 / NG112 Additional Data Repository

## Overview

When a 9-1-1 or 1-1-2 call arrives, the dispatcher often needs more than the caller can say in the first few seconds. They may need vulnerable-person information, subscriber detail, a prior hazard profile for the address, or context from connected systems that already know something important about the call. In NG911 / NG112, that supporting material should arrive as part of the call workflow, not as a scavenger hunt across separate screens.

The Additional Data Repository module gives the platform a standards-based way to assemble and deliver those supporting data blocks for an active emergency call. It lets a PSAP query approved providers in parallel, merge the resulting additional data into the live incident context, and hand that material to dispatch workflows in a form aligned with NG911 / NG112 practice.

```mermaid
flowchart TD
    A[Live Emergency Call] --> B[Additional Data Request]
    B --> C[Provider 1]
    B --> D[Provider 2]
    B --> E[Provider 3]
    C --> F[Signed Additional Data Blocks]
    D --> F
    E --> F
    F --> G[Call Context and Incident Enrichment]
    G --> H[Dispatcher Console]
    G --> I[CAD and Audit Record]
```

**Last Reviewed:** 2026-04-22
**Last Updated:** 2026-04-22

## Key Features

- **Call-Scoped Additional Data Retrieval**: Pull supporting data in the context of a live call rather than as a detached background search.

- **Parallel Provider Fan-In**: Query multiple approved data providers at once so dispatchers receive a fuller picture without waiting through a serial lookup chain.

- **Standard Block Typing**: Organise the returned material into well-understood additional-data block types rather than free-form blobs.

- **Short-Lived Cache for Active Calls**: Reuse recent results during the life of the incident so repeat lookups stay fast while still reflecting that emergency call context is time-sensitive.

- **Signed Block Handling**: Preserve the provenance of returned blocks so a receiving workflow can tell where the data came from and whether it was altered in transit.

- **Audit-Ready Call Context**: Record which additional data was requested, which providers responded, and what was attached to the call context.

- **Provider Flexibility**: Support public safety, digital footprint, entity graph, vulnerable person, and intelligence-style providers behind one NG911 / NG112 retrieval pattern.

## Use Cases

- **Vulnerable Person Alerting**: A dispatcher handling a welfare or medical call receives pre-registered information relevant to vulnerability and care planning without searching manually.

- **Hazardous Address Context**: A PSAP pulls prior premises context or service information that could affect responder safety before units arrive.

- **Caller Context Enrichment**: Subscriber or service context arrives as structured additional data alongside the core call record.

- **Cross-System Emergency Fusion**: An emergency communications centre combines multiple approved sources into one NG911 / NG112-aligned call package instead of asking the call taker to pivot across separate tools.

- **Audit and Assurance Review**: A standards-based log shows which additional data was used during the call and where it came from.

## Integration

- **PSAP NG911 / NG112 Call Handling**: Additional data retrieval becomes part of the live NG911 / NG112 workflow rather than a separate enrichment tool.

- **CAD and Dispatcher Console**: Structured blocks can be surfaced to call takers, dispatchers, and downstream incident workflows as part of the same case context.

- **Voice AI and Silent-Caller Workflows**: Additional data can enrich automated or assisted call handling in the same way it informs human dispatch.

- **NG911 / NG112 Audit and Governance**: Query history and provider outcomes support operational assurance and post-incident review.

## Open Standards

- **RFC 7852**: additional emergency-call data follows the IETF model for attaching structured supporting information to emergency communications.

- **NENA-STA-012**: the repository aligns returned content to the standard NG911 / NG112-style additional-data block types used by emergency communications environments.

- **NENA-STA-021 EIDO**: additional data can sit alongside the broader emergency incident data object model used in NG911 / NG112 operations.

- **W3C Verifiable Credentials Data Model v2.0**: signed block envelopes can preserve provenance in a portable, standards-based verification model.

- **Ed25519**: cryptographic signing of additional-data envelopes uses an open modern public-key signature standard.

- **JSON**: additional-data blocks remain easy to exchange across NG911 / NG112-aware systems using a standard structured payload format.